Process of purifying electrically-conductive materials.



CHARLES C. RUPRECHT, OF CLEVELAND, OHIO.

PROCESS OF FURIFYING ELECTRIOALLY-CONDUCTIVE MATERIALS.

Specification of Letters Patent.

Application filed April 20, 1908, Serial No. 428,057.

To all whom it may concern:

Be itknown that I, CHARLES C. R'ornncnr, a citizen of the United States, residing at Cleveland, inthe county of Cuyahoga and .State of Ohio, have invented a certain new and useful Improvement in Processes of Purifying Electrically Conductive Materials, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings This invention relates to a process of purifying electrically-c onductive materials, such as metals and more particularly to purifying precious metals and lighter metals, such as aluminum. H

It has for its object to provide a particularly simple and eiiicient process whereby impurities may be extracted from such materials and metals, leaving the latter substantially free from all foreign matter.

In carrying out my invention, 1 first melt or reduce to a semi-plastic or fluid condition the material to be purified, either by asource of heat external to the mold or by the use of a mold adapted to melt material placed therein. The outer portion of the mold constitutes in effect one electrode or terminal for an electric circuit, the other electrode or terminal being axially arranged with respect to the former. I then rotate the mold at a high rate of speed, while transmitting current through the molten or plastic mass from the central or inner electrode to the peripheral or outer electrode, or reversely. The centrifugal action imparted to the molten or semi-plastic material will carry to the outer periphery thereof all impurities which are of greater specific. gravity than the material. Reversely, when the impurities are lighter than the material to be purified, the impurities will seek the centrally arranged electrode. In some cases, however, and particularly in the case of the lighter metals, such as aluminum, the density of the impurities is so nearly equal to the density of the metal to be purified that separation by centrifugal action alone will not readily occur. To facilitate such separation, I pass through the material in the direction of the exerted centrifugal force'an electric current. This current, passing radially outwardly or inwardly from one electrode to the other through the nfoltc'n or semi-plastic material, effectually separates the impurities. This separation is secu'iiiigly accompanied and facilitated in some instances by the progressivedissociation and recpnstruction of the molecules 'of'the material through which the current passes.

The passage of the current, whether or not the electrolyte or menstruum be chemically affected by the current, causes the physical transfer of the impurities in the electrolyte or menstruum along-the line of flow of the current. This results in carrying the particles of the impurities to the inneror the outer periphery of the mass, according to the direction of the current, delivering the impurities in the vicinity of the corresponding electrode. For the electrodes, I prefer Patented Jan. 30, 1912. v

to employ some relatively inert refractory material, such as carbon, platinum, or iron, between which the, current will be distributed radially through the mass.

One apparatus for carrying out my process is illustrated in the drawing forming part hereof, wherein Figure 1 represents a top plan view of such apparatus, and Fig. 2 a central Vertical sectional view, taken on the line 2-2 of Fig. 1.

In the aforesaid drawing, 1 represents a central mold-carrier which is rigidly con nected to the shaft :2, said mold-carrier being supported by a suitable standard 3 in which the shaft is journaled, as shown at 4. This shaft is provided near its lower end with a drive gear 5 by means of which it maybe rotated from any suitable source of power (not shown). The lower end of this shaft may 'be mounted in a bearing 6. Shaft 2 projects through the mold-carrier and is provided thereabovewith a circular block 7 of insulating material having thereon a pair of contact rings 8 and 9.

10 and 11 denote a pair of brushes adapted to bear against said contact rings, said brushes being connected respectively by conductors 12 and 13 with a suitable source of electrical power 14;.

The mold carrier 1 is provided with a se-' ries of radially progectmg sleeves or hubs 15,

2t. denotes an electrical conductor connecti g ring 8 with ring '20, and electrodes 17, being insulated from carrier 1 in any suitable manner.

22 denotes'an electrical condimtor connecting ring 19 and electrodes 18 with ring 9.

l/Vith the parts arranged a's described, the operation will. be clear. The material to be purified is introduced into a n'iohh'as through the electrode apertures; shaft 2 is rotated by means of gear 5 and current is suiliplied from the generator it to the suitable electrodes, either the inner or the outer, as condititms may recpiire. \Vhen the im purities to he separated are heavier than the material to he purified. the current will he transmitted through such n'iaterial trout the inner to the outer electrode of each mold. hen the impurities are lighter than the material to he purified, the current will be transmitted in a. reverse direction, that is to say, iron] the outer electrode to the inner electrode at each mold. The will collect; at one end of the mold, caving the purified material in the remaining portion ot the mold. The passage of; the current through the mass within the mold tends to maintain the mass m a molten or semiplastic condition.

By the process and ap )aratus described herein, it am enabled to ellectively and econoi'nii'zally remove from elcctrically-conduetive materials (whether metal or otherwise) impurities" which, owing to their approximation in density to the density 0'. such materials, cannot be removed by centrifugal action alone. I

Having thus described my invention, 1 claim:

1. The process of purifying electrically conductive materials which consists in reim urities during the materials to a fluid condition, ro-

tating the fluid mass, and passing an electric current radially lllll'UtWl'l such mass.

The process of purifying electrical-lyl conductive n'iatcrials which consists in reducing the same to a fluid condition, rotating the fluid mass to subject the same to C(EI'ltLl'iEHQjdl action and passing through the rotating mass a current in the direction of the exerted centrifugal force.

3. The process of purifying electrically conductive materials which consists in reducing such materials to a molten or semiplastic condition, rotating the molten or semi-plastic mass, and passing an electric current through such mass radially from the central portion thereof tothe peripheral portion thereof.

4. The process of purifying electricallyconductive materials which consists in reducing-55inch materials to a molten or semiplastic condition, rotating the molten or semi-plastic mass to subject the same to centrifugal action and passing a current ra' dially through such mass.

The process of purifying electricallyconductive llltllQI'ltllS which consists in reducing such materials to a molten or semiplastic condition and passing an electric current through the molten or semi-plastic mass thus obtained, to drive the impurities toward one of the electrodes by means of -\\'hieh current is passed through such mass.

6. The process of purifying electrically coluluctivc materials which consists in reducing to a molten or semi-plastic condition the material to be purified, rotating such material, passing through the material an electric current in the direction of the exerted centrifugal force produced by such rotation and n'iaintaining such material in a molten or semi-plastic condition during the passage of the current thercthrough.

In testii'nony whereof, I hereunto atlix my signature in the presence of two witnesses.

(Jilin- LES C. RUPRECIIT.

\Vitnesses J. B. Ilium, A. J. llitnsoN. 

